Cutting unit with guard teeth and hair-cutting device
AssigneeKoninklijke Philips N.V.
InventorHannes Floessholzer
Life of this patent
Estimating the term…
Abstract
To minimize the risk for injuries due to hooked hair catching teeth, but still have a reasonable hair-cutting efficiency, a cutting unit (107) for a hair-cutting device (100) having two blades (202, 206) moving relatively to each other with at least one of the blades (202, 206) being toothed is proposed, wherein at least some teeth (208) have a larger cross-sectional area (CA) at their free end (210) than at their end (212) making the junction with the blade (206), wherein the larger cross-sectional area (CA) is 0.32 mm2 or more and wherein the shape of the larger cross-sectional area (CA) is such that the tooth (208) surface oriented to face the surface (305) with hair (301) to be cut when cutting has a larger distance to the middle axis (M) than the equivalent surface of the blade-side-end (212).
Claims17
A hair-cutting device, comprising:
- a reciprocating blade having a cut tooth;
- and
- a stationary blade having a guard tooth, wherein the guard tooth has a first end joined to the stationary blade and a second end that is free, the second end having a larger cross-sectional area than the first end, wherein the second end comprises a lower surface bulge in a lower surface of the guard tooth protruding downward from a middle axis of the guard tooth to a lower end, the lower surface bulge being configured to face skin during operation of the hair-cutting device, and wherein the second end further comprises an upper surface bulge in an upper surface of the guard tooth, wherein the bulge in the upper surface of the guard tooth protrudes upward from the middle axis of the guard tooth to an upper end, wherein the upper surface and lower surface bulges have a combined cross-section that has a width and a height, wherein the height is defined as a distance from the upper end to the lower end and the width is a thickness of the second end perpendicular to the middle axis and the height, wherein a center of mass of the second end including the upper surface bulge and the lower surface bulge is below the middle axis.
A hair-cutting device, comprising:
- a lower end portion including a rechargeable battery;
- and
- a cutting head comprising,
- a reciprocating blade having a plurality of cutting teeth;
- and
- a stationary blade having a plurality of guard teeth, wherein at least some of the guard teeth have a first end joined to the stationary blade and a second end that is free, the second end having a larger cross-sectional area than the first end, wherein the second end comprises a lower surface bulge in a lower surface of the guard teeth protruding downward from a middle axis of the guard teeth to a lower end, the lower surface bulge being configured to face skin during operation of the hair-cutting device, and wherein the second end further comprises an upper surface bulge in an upper surface of the guard teeth, wherein the bulge in the upper surface of the guard tooth protrudes upward from the middle axis of the guard teeth to an upper end, wherein the upper surface and lower surface bulges have a combined cross-section that has a width and a height, wherein the height is defined as a distance from the upper end to the lower end and the width is a thickness of the second end perpendicular to the middle axis and the height, wherein a center of mass of the second end including the upper surface bulge and the lower surface bulge is below the middle axis.
Dependencies are inferred from the claim text.